The Rolls-Royce Silver Ghost chassis was built during the years 1907 to 1925 with a total number of 6,703 having been produced. It takes its name from an epithet used for the first production model which was fitted with an open-tourer body painted silver and from the silence of its engine when running.

It is thought that fewer than 1,000 remain today.

The engine has 6 cylinders and a cubic-capacity of 7.5 liters (453 cid). It will cruise at 65-70 miles per hour and covers 10-12 miles per gallon of regular fuel.

The Silver Ghost model won many reliability trials during its production including the 1913 Alpine trials. It was equipped with armoured and ambulance coach work for service during the First World War. Lawrence of Arabia spoke highly of the reliability of his Silver Ghost and it was from these events that the car gained the reputation of being 'simply the best car in the world.'

The car has the red RR insignia, changed to black following the death of Sir Henry Royce in 1934. The Hon. Charles Rolls died in a ballooning accident in 1910.

68ZG is now fitted with an Open Tourer body to a design by the famous Hooper Coach Building Company. It was originally fitted with Hooper Landaulette body when delivered to C. N. Nairn esq of Broughty Ferry, Scotland in 1923. It was fitted with its current coachwork in 1965 by M. Phillips of England.